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US 4,789,288 AGranted
Anti-cross threading screw
AssigneeBuell Industries, Inc.
InventorFrancis C. Peterson
Life of this patent
Estimating the term…
Abstract
A screw having a tapered and offset tip with a partial thread prevents cross-threading of the screw when inserted into a nut. The offset tip is a section of a conical frustum. The axis of the conical frustum section is offset from the axis of the shank of the screw. The conical frustum section is defined by those portions of a conical frustum contained within the outer radius of the screw shank. The partial thread is located on the side of the tip facing the direction of offset of the tip.
Claims9
A screw, comprising:
- a head;
- a threaded shank projecting from said head, said shank having a tip at its axial end opposite said head, said tip comprising a section of a circular substantially conical frustum having a central axis which is offset from the central axis of said shank, said offset facing side having a partial thread formed thereon.
A screw for preventing cross-threading, comprising:
- a head;
- and
- a cylindrical threaded shank projecting from said head, said shank having at its end opposite said head a circular substantially frusto-conical section having a central axis which is offset from the longitudinal axis of said shank.
A screw for preventing cross-threading, comprising:
- a head;
- and
- a cylindrical threaded shank projecting from said head, said shank having at its end a partially threaded circular frusto-conical section, the centerpoint of said frusto-conical section being offset from the longitudinal axis of said shank by a distance equal to between about 10 to about 20 percent of the diameter of said shank.
Dependencies are inferred from the claim text.